In German Pat. No. 34 32 548 there is described a continuous press for hot pressing a mat for making chipboard, fiberboard, laminated board and other composite materials comprises a press frame, a lower pressing plate with a heated platen, an upper pressing plate with another heated platen and endless press belts guided about the pressing plates with the aid of guide drums, which form an entrance mouth in the vicinity of the guide drums and a press gap in a pressing region.
The press belts are guided in the pressing region on roll rods, which circulate between the hot platens and the press belts and the roll rods are guided around the upper and lower pressing plates on a guideway with the help of an upper and lower roll rod circulating mechanism having guide chains and a roll rod feed mechanism with entrance-end roll rod feed wheels.
The lower pressing plate is located in the press lower portion while the upper pressing plate is located in the press upper portion.
By a "laminated board" I mean one used in making a circuit board for a printed circuit, such as a board with an insulating substrate or core having a glass fiber reinforcement embedded in an epoxy resin system and having one or more metal foil layers. The roll rod feed mechanism feeds the roll rods between the press belts and a heated platen or upstream associated platen in the pressing region.
In the press of German Pat. No. 34 32 548, the press belts run freely in the region between the guide drums and the roll rod feed mechanism. Of course, depending upon to the thickness of the mat fed into the mouth pressing can occur even in this region. However in this region the pressing is not controllable although such a control is often highly desirable according to the mat being pressed.
To influence the course of the pressing in the entrance region in continuous pressing as described above other devices or mechanisms are already known as described in German Pat. No. 22 22 419. Thus slide shoes are connected in the pressing region. However with the slide shoes continuous pressing of the above described type with roll rod circulation and roll rod feed mechanisms is barely possible and no operating adjustment for a variety different pressing course curves is possible.